Workpiece holders or jigs are well known in the art. These devices are utilized to hold one or more items in a desired position while a manufacturing process is performed. An apparatus for holding two metallic components in a fixed abutting relationship for welding is typical of this technology. In a specialized category of workpiece holders, the item(s) are held in place by magnet force. For example, U.S. Pat. No. 2,443,582 shows a work holder of the kind used for holding component metal parts in place while they are being connected together, and is especially useful for welding. The device includes a plurality of electromagnets mounted on a frame. The electromagnets are arranged so as to generally correspond with the shape of the work structure to be produced. U.S. Pat. No. 2,676,504 defines a magnetic face plate for either permanent or detachable mounting on the jaws of a vice. The device also includes suction means for holding objects on nonmagnetic material to the face plate. U.S. Pat. No. 3,210,068 depicts a magnetic spacing tool for establishing a uniform gap of a desired width between two objects to be welded together. The spacing tool includes an elongated spacing member or plate having a cutout which forms a handle portion. The thickness of the spacing tool is equal to the desired spacing to be established between the adjacent portions of the workpieces. U.S. Pat. No. 3,491,995 disclosed an work holding apparatus for tack welding, comprising a mobile welding jig yieldably supported by castor wheels for movement to a desired location on a steel plate straddling a steel beam to which the plate is to be tack welded. Magnetic gripping devices anchor the jig frame to the steel plate while retracting the castor wheels so that the beam and plate are clamped together when a fluid power operated piston engages the beam. U.S. Pat. No. 4,492,367 comprises a magnetic holding apparatus for holding an object, such as a furnace or kiln block, in a predetermined position relative to an external metal member, such as the metallic shell of furnace or kiln. The apparatus includes a foot assembly which is adjustably supported on a rod member, which is in turn supported by the lower side of a magnet. The upper side of the magnet is removably magnetically affixed to the metallic shell so as to secure the apparatus thereto, thus enabling the foot assembly to hold the object against the magnetic shell. U.S. Pat. No. 4,524,959 consists of a holder of pipes or pipe joints for welding, where one of the pipes or pipe joint is held by three pipe abutting members mounted in angularly spaced relation on a common holder with the position of the pipe abutting members being adjustable by a screw bar.
The aforementioned devices require that the workpiece be precisely clamped or otherwise secured to the jig. This is often a time consuming process, requiring numerous clamping, unclamping, adjusting, and reclamping steps, to ensure that the workpiece is properly positioned.
A Welder's Vice Set manufactured by Bessey, Germany includes a cast iron base having two jaws in a fixed 90.degree. relationship, and a moveable jaw which clamps the workpieces against the fixed jaws. A magnetic welding fixture Model AD-1307 manufactured by MAGNETOOL INC., 505 Elmwood, Troy, Mich. 48083-2755, adjusts and locks securely at any angle from 45.degree. to 90.degree.. A magnetic welding fixture MAC 9 manufactured by BUNTING Magnetics Co., 500 S. Spencer Avenue, Box 468, Newton, Kans. 67114-0468 illustrates a heavy-duty variable magnetic clamp which may be set at any angle from 45.degree. to 90.degree., and has angles marked in 15.degree. increments. Model MAC 2 comprises an adjustable magnetic clamp which is adjustable from 25.degree. to 280.degree..